IMPROVED OOCYTE QUALITY IS OBTAINED WITH FOLLICLE-STIMULATING-HORMONEALONE THAN WITH FOLLICLE-STIMULATING-HORMONE HUMAN MENOPAUSAL GONADOTROPIN COMBINATION

The aim of this study was to compare the efficacy of pure follicle sti mulating hormone (FSH) with that of FSH/human menopausal gonadotrophin (HMG) combination in downregulated cycles, A total of 357 patients wa s evaluated retrospectively. Sixty percent of patients in the FSH grou p and 55 % in the FSH/HMG group were new; the others were repeat patie nts, Ovulation was suppressed with leuprolide acetate in all patients, followed by either FSH (n = 218) or FSH/HMG (n = 119), There was no d ifference in patients' age, infertility factors, number of ampoules us ed, length of stimulation, oestradiol levels on day of human chorionic gonadotrophin (HCG) administration, number of oocytes recovered or th e number of embryos transferred, Also, nuclear maturity at aspiration and fertilization rates were not different between the two groups, FSH stimulation resulted in a significantly higher percentage of mature o ocytes that showed the typical 'mature' morphological characteristics (P < 0.0001), The clinical pregnancy rates per transfer were 40 and 28 % in patients stimulated with pure FSH and FSH/HMG respectively (P < 0 .05), The significantly higher number of immature oocytes matured in v itro in the FSH/HMG group (P = 0.001) suggests a possible effect on in -vitro maturation, due to luteinizing hormone present in HMG, The diff erence in mature oocyte quality may be an important determinant in the higher pregnancy rates for the FSH-stimulated patients.